What Germany would need to become a naval power after 1650

How could Germany become a genuine naval powerhouse starting just after the Thirty Years' War?

Unify politically, invest continuously in maritime infrastructure, and build overseas commerce whose protection creates a lasting strategic case for a navy.

Continuous investment in dockyards and maritime institutions is necessary but not sufficient. A fragmented Germany faces strong continental threats from France and Russia, so rulers naturally prioritize armies. Political unification and a longer secure coastline would make naval defense more compelling. An alternative route is to preserve Hanseatic commercial strength and encourage German trading cities to acquire overseas posts whose protection requires warships. Merchant wealth, colonies, and naval infrastructure would then reinforce one another. Fleet building depends on state geography and political economy, not simply the decision to order ships.